Glycogenosis is a rare hereditary metabolic disease associated with a deficiency of one of the enzymes involved in the synthesis of glycogen. Glycogenols are a relatively small group of glycogen polymorphisms, which are characterized by a deficiency of one of seven naturally occurring isomers (1-3, 4, 6 or 7, l-O), the accumulation abnormalities of which have common biochemical and histological features.